When a message fails to be delivered to a recipient, one of the following failed delivery error codes will show in the API Response along with the explanatory error message:
| Error Code | Error Message |
|---|---|
| 000 | Unknown Error |
| 001 | It indicates an unknown or unrecognized recipient, often due to non-existent or invalid subscriber information. |
| 009 | Mobile station authentication failure, often due to blacklisted or subscribed subscriber numbers. |
| 011 | The mobile subscription of this number doesn`t support SMS |
| 12 | Blocked - Fraud URL |
| 027 | The destination numbers provided during the submissions were unreachable. |
| 034 | Mobile subscriber was not reachable due to a network operator protocol error. |
| 069 | The telecom company has disconnected the phone number from service, due to unpaid bills for example. |
| 121 | This error is temporary and related to the handset, typically resolved by restarting the device or reinserting the SIM card. |
| 131 | The operator suspended the subscriber`s service, usually because of unpaid bills |
| 999 | Message rejected due to user`s subscription to DND (Do Not Disturb) services |
| 20 | Network Not in Coverage |
| 21 | Unknown Network |
| 22 | Not Sent Scheduled SMS |
| 30 | Invalid Mobile Character |
| 31 | Invalid Mobile Length |
| 32 | Invalid HLR Mobile |
| 7777 | SMS rejected by the mobile operator for the attempted destination address |